Preheat your oven to 375°F (190°C). Line two baking sheets with parchment paper and set aside.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large bowl with a stand mixer (or using a hand mixer), cream together the softened butter and granulated sugar on medium speed until light and fluffy, about 2-3 minutes.

Add the egg, vanilla extract, lemon zest, and fresh lemon juice to the creamed mixture. Beat on medium speed until well combined, scraping down the sides of the bowl as needed.

Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.

Gently fold in the raspberries using a rubber spatula. If using frozen raspberries, do not thaw them first to minimize bleeding into the dough.

Drop rounded tablespoons of cookie dough onto the prepared baking sheets, leaving about 2 inches between each cookie. You can also use a small cookie scoop.

Bake for 10-12 minutes, or until the edges are lightly golden and the centers are just set. The cookies may appear slightly underdone in the center, which is perfect for a soft, chewy texture.

Remove the baking sheets from the oven and let the cookies cool on the sheets for 5 minutes before transferring them to a wire rack to cool completely.

While the cookies cool, prepare the lemon glaze (if desired). In a small bowl, whisk together the powdered sugar and 2 tablespoons of lemon juice until smooth. If the glaze is too thick, add more lemon juice or a tablespoon of milk, a tiny bit at a time, until you reach a drizzling consistency.

Once the cookies are completely cool, drizzle them with the lemon glaze. Let the glaze set before serving or storing.